1. Field of the Invention
This invention relates generally to vehicle blind spot identification, and more particularly to a method and system for alerting a driver or pedestrian to the presence of vehicles, pedestrians, or objects in their blind spot.
2. Description of the Related Art
A major contributor to vehicle accidents is blind spots in the rear side perspective views of a driver. The driver blind spots occur when a second vehicle is traveling slightly behind and along side the driver's vehicle in an accompanying lane. Blind spot accidents occur when a driver switches lanes and is unaware that a second vehicle is occupying the intended new lane. As a result a collision between the two vehicles occurs. Driver blind spots exist despite the fact that vehicles are equipped with a series of view mirrors to assist the driver. The series of mirrors are generally configured as a rear view mirror that is internally mounted above the front windshield in the center of the vehicle, and one or two external side mirrors that are mounted on the front side portions of the vehicle. The series of mirrors are designed to allow the driver to have a rear view without having to turn their head to the rear.
External side mirrors and the rear view mirror reduce the driver blind spots. However, it is nearly impossible to eliminate all blind spots with mirror adjustment. The exact area of the driver blind spot varies depending on the type of vehicle and height of the driver. Accordingly, rear blind spots for midsize sedans range between 12-17 feet behind the vehicle, mini vans range from 13-23 feet, and midsize trucks between 29-51 feet. Each of the ranges accounts for various heights of the driver. Tractor-trailer drivers encounter a much larger visual impairment. The blind spots are located on either side, the rear, and directly in front of the tractor-trailer. In the US, over 200,000 accidents between cars and trucks occur each year. Eighty percent of car drivers involved in tractor-trailer accidents don't survive.
Current efforts to solve the driver blind spot problem have been directed towards developing a blind spot monitoring system that will alert the driver of vehicles that are present in their blind spots. Blind spot monitors include, a camera mounted on the back bumper of a car that shows the driver video feeds of objects behind the car when it is in reverse. Another option called VORAD (Vehicle On-board Radar) transmits and receives microwave signals, alerting a driver to obstructions. The VORAD system can penetrate through environmental conditions such as darkness, fog, dust, and smoke. The VORAD system is currently used on busses to detect vehicles along the side and in front of the bus. A lane-changing alarm is another product available to consumers. The lane changing alarm is designed using a passive infrared sensor that detects the heat of a moving tire and a light emitting diode (LED) that flashes when vehicles, pedestrians, or other objects are in the side blind spot. A product designed for commercial vehicles employs ultrasonic sensors mounted on the outside of the vehicle to detect obstructions at slow speeds.